1. Field of the Invention
The present invention relates to an ink jet recording head and an ink jet recording apparatus.
2. Description of the Related Art
Heretofore, ink jet recording technology, particularly bubble jet recording technology has been rapidly popularized, as color printing and personalized printing have advanced in printing in an office. In short, a bubble jet recording head can easily achieve a high density, a structure having many nozzles and the formation of small liquid droplets, and a recording apparatus can extremely easily achieve compactness, a low cost and a high quality, and is characterized by being easily arranged for various applications by simply changing the design of the head, thereby becoming the principal part of the office.
As regards designing with high quality, particularly with high image quality as described above, the ability to maintain the proper discharge direction during ink discharge exerts a powerful effect on designing with high image quality. That is, in the case where deviation (slippage) in the discharge direction causes an ink droplet to deviate from a position where the ink droplet is to be adhered (ideal placement) and the ink droplet adheres to a position before it reaches the medium (paper in many cases) to which the ink is to be adhered, since the ink dopler does not get fixed on the proper portion of the medium, an unprinted portion of the medium, having a blank stripe, may be produced.
Since the stripe is easily recognized by human vision, it is significant as a deterioration factor of an image, thereby posing one an important subject in ink jet recording. To put it concretely, for example, in the case where a recording head having a discharge amount of 8 pl is used for printing, though it depends on the mode of printing, a deviation of several 10 xcexcm on the medium is sufficiently recognized as a stripe on the medium. The deviation in the discharge direction is determined by the direction in which the ink droplet is discharged and the distance between the ink discharge port and the medium. That is, the closer the discharge direction to the ideal placement, and the shorter the distance between the ink discharge port and the medium, the smaller the deviation.
If the distance between the ink discharge port and the medium is approximately 0 (zero), the deviation will be 0 (zero) regardless of the discharge direction, but it is difficult to reduce this distance for the following reasons.
1. In the case in which the discharge port comes in contact with the medium, an obstruction may be produced in the discharge port. Furthermore, the ink that has already hit the medium may be scratched by the contact, thereby causing the image to deteriorate.
2. Even in the case in which the discharge port does not contact the medium, as the medium to which the ink adheres absorbs the ink by bringing the discharge port close, the ink swells to become uneven (cockling), the distance between the discharge port and the medium becomes non-uniform, and in the worst case, such an obstruction as described in point 1) above may be produced. Furthermore, since the head side has a convex portion on the medium side rather than merely the ink discharge port, it is necessary to expand the distance between the medium and the ink discharge port by the height of the convex portion. The convex portion may incorporate a sealing material to protect an electric connection electrode from ink formed on an insulation basic body formed thereon with an ink flow path and an energy generating member for discharging the ink in order to transmit an electrical signal or electric power to the energy generating member. In the case where there is no sealing material, since the ink is an electrolyte in many cases, there may be produced an obstruction which causes a wiring electrode or the electric connection electrode necessary for driving the energy generating member formed on the insulation basic body to corrode or dissolve or the like.
3. Therefore, sealing material is necessary, but the sealing material needs to be approximately 0.2 to 0.6 mm high for the distance of 1 to 2 mm between the ink discharge port and the medium, which in turn exerts an adverse influence in terms of deviation of ink placement, which causes the above-mentioned stripe.
An object of the present invention is to provide an ink jet recording head and an ink jet recording apparatus capable of improved reliability by making the sealing material not to be convex.
An ink jet recording head of the present invention comprises a flat substrate having an end face and front and back flat main surfaces having a larger area as compared to the end face, an energy generating member for generating energy to be utilized to discharge the ink from a discharge port formed on the front flat main surface side of the substrate, a wiring electrode connected to the energy generating member formed on the front flat main surface of the substrate, and a connection electrode, connected to the wiring electrode, for receiving an electrical signal supplied from outside of the substrate, wherein the connection electrode is provided on another surface different from the front and back flat main surfaces of the substrate. Furthermore, an ink jet recording apparatus of the present invention comprises the ink jet recording head and a member for mounting the ink jet recording head.
According to the present invention, it is possible to make the sealing material not to be convex, thereby obtaining an effect to improve the reliability of the ink jet recording head.